Work holding fixture



J 9 .5 P. E. OLSON 3,188,077

WORK HOLDING FIXTURE Filed Dec. 20, 1961 2 Sheets-Sheet l v w y Y m 19 m4 I i\ ,i i

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June 8, 1965 p OLSQN WORK HOLDING FIXTURE 2 Sheets-Eihaet 2 Filed D60.20, 1961 3,188,077 WQRK HOLDING FIXTURE Philip E. Olson, Rockford, Ill.,assignor, by memo assignments, to Rockford Machine Tool Co., acorporation of Iilinois Fiied Dec. 20, 1961, Ser. No. 160,720 3 (Ilaims.(Cl. Z69226) This invention relates to work holding fixtures and moreparticularly to a fixture for use in a metal cutting planer or the like.

It is the general object of the invention to provide a new and improvedwork holding fixture adapted to clamp and lock one or more work pieceswith considerable force.

It is another object to provide such a fixture with means for breakingthe clamping lock on the work piece to permit removal thereof.

Other objects will become readily apparent from the foilowingdescription, taken in connection with the accompanying drawings, inwhich:

FIGURE 1 is a fragmentary plan view of a preferred form of theinvention;

FIGURE 2 is an enlarged end elevation, partly in section, along line 22of FIGURE 1;

FIGURE 3 is an enlarged section along line 3-3 of FIGURE 1; and

FIGURE 4 is a fragmentary view along line 4-4 of FIGURE 3.

As shown in the drawings, the invention comprises an attaching plate 10and a base 11 secured thereto. The base has a pair of opposed flanges 12and 13 which form the outer stationary jaws of a pair of vises 14 and15. There are preferably a plurality of movable jaws for each vise,herein shown in the form of members 16 and 17 for the vise 14, andmembers 18 and 19 for the vise 15. The jaw members 16 and 17 areslidably supported and guided in pairs of upstanding portions 20 and 21on the base 11 for movement towards and away from the stationary visejaw 12. Similarly, the jaw members 18 and 19 are slidably supported andguided in pairs of upstanding portions 22 and 23 on the base 11.

A high torque electric motor 25 is adapted to actuate the jaw members 16and 18 and a similar high torque electric motor 26 is adapted to actuatethe jaw members 17 and 19. V

The actuating or drive mechanisms between the motors and the movable jawmembers are of a high torque multiplying type so that by the use of hightorque motors extremely strong clam-ping action is obtained upon workpieces when placed in the Vises. The drive mechanism, as shown in FIGURE2 for the jaw member 16, comprises a screw and nut device with a nutelement 27 carried on the jaw member and secured thereto by screws 28.The screw element 29 is formed on a shaft 30 which has splines 30thereon and has a worm wheel 31 splined thereto and also has a portionat its other end forming the screw element 32 of a similar screw and nutdevice for the jaw member 18. The worm wheel is rotatably supported onball bearings 33 and 34 supported in a gear casing 35 which in turn isfixed to the base 11. A worm 36, meshing with the worm wheel 31, isformed on a shaft 37 which is supported in the gear casing 35 onantifriction bearings 38 and 39 (FIGURE 3).

United States Patent ice In order to facilitate the unclamping of workpieces in the Vises, a lost motion device is provided in the drivemechanisms. As shown best in FIGURES 3 and 4, the drive mechanismincludes a pinion 40 on the shaft 41 of the motor 26, and a meshing gear42 supported on a sleeve bearing 43 carried on a hub 44 keyed at 45 tothe Worm shaft 37. A drive pin 46 is screwed to the gear 42 in aneccentric position on one side thereof so as to move in a circular pathadjacent the gear. An arm 47 is formed integrally with the hub 44 andextends radially therefrom into the path of the pin 46. Thus the gear42, from a position wherein the pin 46 is against one side of the arm47, can turn through most of a full revolution in a reverse directionbefore the pin engages the other side of the arm. This affords time forthe motor to accelerate in the opposite direction and enables the pin toproduce a hammer-blow on the arm to break the friction in the drivemechanisms and unclamp work in the vises.

To insure equal pressure on the movable jaw members of both vises, thesplines 30' are shorter than the hub 31 of the worm wheel 31, thusenabling the shaft 30 to move laterally from .the position shown inFIGURE 2.

In operatiomwith the movable jaws withdrawn, work piecesmay be placed inthe Vises 14 and 15. Upon energization of the motors 25 and 26 in aforward direction, the jaws 16 and 17 move to close the vise 14 and thejaws 18 and 19 move to close the vise 15 on the work pieces. During thisoperation the drive pin 46 of the lost motion device is in engagementwith one side of the arm 47 and the high torque of the motors and thehigh torquemultiplying gearing produce an extremely strong clampingforce in the vises. After the cutting operations have been performed onthe work pieces, reversal of the motors to unlock the vises, produceshammer-like unlocking blows by the lost motion devices, thus insuringthe opening movements of the jaw members.

I claim:

1. A work holding fixture comprising, in combination, a base havingmeans thereon forming one jaw of a work holding vise, a member slidableon said base forming the opposite jaw of said vise and means for movingsaid slidable jaw member comprising a screw and nut device, one elementof which is carried on said jaw member, a worm and worm wheel devicehaving the worm wheel connected to the other element of the screw andnut device, a high torque electric motor having a pinion on its shaftmeshing with a gear rotatably mounted on a shaft carrying said worm, anda lost motion drive means between said gear and shaft comprising a drivepin positioned eccentrically on one side of said gear and an arm fixedto said shaft and extending radially therefrom in the path of said drivepin.

2. A work holding fixture comprising, in combination, a base havingmeans thereon forming one jaw of a work holding vise, a member slidablymounted on the base forming the opposite jaw of said vise, first meansto move said member, reversible power operated means, gearing meansconnecting said power operated means to said first means and including alost motion device on said gearing, said lost motion device having adrive pin affixed to the gearing means and a two-sided arm afiixed tosaid first means so that when said power operated means drives saidgearing in one direction, the drive pin arsaow a base having meansthereon forming one jaw of a work 10 holding device, a member slidablymounted on the base forming the opposite jaw of said vise, first meansto move said member, a high torque reversible electric motor, andgearing means connecting said motor to said first means including apinion on the motor shaft meshing with a gear rotatably mounted ona'parallel shaft, and a lost motion device on said gearing means betweensaid gear and said parallel shaft to drive said first means in either aclockwise or counterclockwise direction depending on the direction ofsaid high torque reversible electric motor.

References Cited by the Examiner UNITED STATES PATENTS 705,197 7/02Blood 269-224 X 1,635,758 7/27 Lemon 74425 X 2,238,434 4/41 Oberhofiken269142 X 2,793,551 5/57 Ford 81-52.? 2,929,298 3/60 Hill 269l52 X3,063,708 11/62 Wollenhaupt 269--216 ROBERT C. RIORDON, PrimaryExaminer.

5 THOMAS J. HICKEY, Examiner.

1. A WORK HOLDING FIXTURE COMPRISING, IN COMBINATION, A BASE HAVINGMEANS THEREON FORMING ONE JAW OF A WORK HOLDING VISE, A MEMBER SLIDABLEON SAID BASE FORMING THE OPPOSITE JAW OF SAID VISE AND MEANS FOR MOVINGSAID SLIDABLE JAW MEMBER COMPRISING A SCREW AND NUT DEVICE, ONE ELEMENTOF WHICH IS CARRIED ON SAID JAW MEMBER, A WORM AND WORM WHEEL DEVICEHAVING THE WORM WHEEL CONNECTED TO THE OTHER ELEMENT OF THE SCREW ANDNUT DEVICE, A HIGH TORQUE ELECTRIC MOTOR HAVING A PINION ON ITS SHAFTMESHING